In loading, unloading, transport and treatment of, e.g., farmed fish to or from a net cage and/or slaughterhouse, conventional so-called well boats are used. A well boat may be a very advanced and expensive vessel that is equipped with a number of tools in addition to the conventional well or basin that should hold farmed fish or other aquatic organisms. The well boat is generally provided with a loading/unloading system, cleaning system, oxygen supply system, penetration system, fish counter, various lifting systems/cranes, washing systems and living quarters/lounges for the workers on board. A conventional well boat often services a number of fish farms and must run in shuttle traffic between different net cages and slaughterhouses. To avoid the spread of various types of fish diseases or parasites, e.g., ILA, PD, IPN, HSMB, Vibriose, Furunculosis, sea lice, etc., there are requirements for the cleaning of equipment and hull and requirements for observing quarantine periods/procedures. The costs of operating a well boat are high and efficiency is relatively low.
There has been and is now considerable focus on the negative consequences resulting from fish breeding and well boat transport of live fish from hatchery to cage, between cages, or from cage to slaughterhouse. The negative consequences are especially associated with fish escape, sea lice, spread of disease and, not least, the welfare and quality of the fish. At the beginning of 2013 the Norwegian Food Safety Authority (Mattilsynet) was commissioned by the Ministry of Fisheries and Coastal Affairs to review various measures intended to reduce the risk of disease dissemination in transport of farmed fish with a well boat.
“The Norwegian fish breeding industry is completely dependent on transporting fish with well boats. With the growth of the industry, the well boat traffic has also increased accordingly, and the boats have become larger. The fish are moved over relatively large distances, and transport of farmed fish in well boats is generally carried out with open bottom valves. This entails a risk of disease dissemination.
“When transporting table fish there is a need to reduce the risk that infection will be spread from the fish in the well boat to fish in aquaculture installations and to wild fish. When transporting juveniles there is first and foremost a need to reduce the risk that the fish in the well boat will be infected via transport water taken in during transportation. Similarly, in the transport of broodfish it is necessary both to reduce the risk that the broodstock will be infected and to reduce the danger of disease dissemination to the surroundings.
“To reduce the risk of infection during transport of farmed fish with a well boat, the Norwegian Food Safety Authority has proposed amendments to the Regulations of 17 Jun. 2008, No. 820, on the transport of aquaculture animals (the transport regulation) . . . . The proposal means that, from 1 Jan. 2019, it will be required that all well boats shall treat transport water with an approved disinfection method and with disinfection equipment that is proven to be effective. The disinfection efficacy and capacity must be sufficient to handle all water intake or discharge water depending on whether it is hatchery fish, table fish or broodstock that is being transported.”
The Norwegian Food Safety Authority also proposes that, “from 1 Jan. 2015, there shall be a requirement for geographic tracking of well boats, and the requirement that information on the position of the bottom valves shall be registered and logged automatically on the boat.” A draft of the regulation for amendment in the regulations relating to transport of aquaculture animals can be downloaded on the www.mattilsynet.no homepage.
Despite a strong focus on approaches to the problems relating to transport of live fish and stricter regulations, there are still major challenges. Loading and unloading of live fish to and from a well boat, for example, is an operation involving a high risk of escape, either due to damage/injury to a cage by the well boat when anchoring at the edge of the cage, or through technical or human error in the loading and unloading system during operation.
Escape of fish not only causes considerable financial loss for the breeder, but it also constitutes a major environmental problem. In the extreme consequence, the fish can mingle with wild fish and ruin its genetic diversity. In addition, escaped fish may be infected with various types of parasites and diseases that can in this way be transferred and spread to wild fish strains in the area and to neighboring fish farms. Hence there is a need for solutions that will prevent escape.
The current use of open holding cages is also a subject of discussion, with more and more countries today requiring the use of closed installations at sea or on land. Closed systems could provide for better fish welfare, which in turn results in better quality. An alternative to the use of holding cages, whether open or closed, is direct slaughtering at the cage or at the quay. The latter method will lead to reduced salmon prices and prevent optimal utilization of the slaughterhouse's capacity.
Today there is high mortality involved in smolt stocking. The survival capability is affected by water quality, velocity of flow, temperatures, light, and other factors. A controlled familiarization environment for production of large smolt is an important measure to reduce mortality. It has been demonstrated, inter alia, that low salinity and water flow produce healthier and more resistant fish. Stocking of large smolt also means that the salmon will on average spend fewer months in the sea, which contributes toward reducing the risk of financial loss. The operational process can also be managed so that it is possible to slaughter and deliver the fish steadily throughout the entire year.
Today there are few solutions and measures for preventing infection once disease has been established, aside from slaughtering. A closed system thus could conceivably function as a quarantine facility, wherein medicinal measures can be undertaken without affecting the surroundings. It is also a paradox that today the same well boat that transports healthy fish is used to transport sick fish—a practice which quite clearly constitutes an infection risk. There are, however, special requirements for quarantine periods and standards for washing and disinfecting, but these impose unnecessarily high costs on the breeder as a result of the downtime involved.
With respect to sea lice, there are currently used large quantities of insecticides (for example, pyrethroids/pyrethrin or other similar agents which, inter alia, attack and restrain enzymes involved in the chitin production and thereby retard the development of the shell and other chitin-containing organs, for example, reproductive organs and gripping organs in salmon lice) and other medicines to keep down the proportion of parasites. Flubenzurons are examples of another toxin that is used. The disadvantage of such treatment is that the salmon have to work themselves “clean” for several months after they have been exposed to the toxin.
In the case of lice treatment, it is currently required that this be done in a closed system (net cages, or well boats). The drawback is that it cannot be proven with certainty that the treatment has been sufficient. The most extreme consequence is that the parasites are only knocked out temporarily, and will gradually be able to develop resistance to these agents. The wild fish that live around the fish farms will be deloused only to a slight degree and, as a result, could be weakened and then die from the injuries they sustain. In addition, fish that have escaped or been infected with lice could spread the resistant salmon lice to other fish and thereby further damage the wild fish stock.
Algae growth in the sea as a result of an accumulation of nutrients from food, etc., is also a problem that can have negative consequences for the fish breeding industry. For example, four to six cages having up to 200,000 salmon in each will produce excrement corresponding to that produced by a city of about 60,000 people. Large algae concentrations can give the water an undesirable color, smell and taste, and certain algae types can even develop toxins that can be injurious to animals and people. In addition, the growth of large quantities of algae could render the water oxygen-free, which could be a problem, inter alia, in breeding farms for fresh water fish.
Consequently, there is a need for a breeding facility for fish and also other aquatic organisms (crustaceans [crawfish, lobsters]), mollusks [mussels, scallops, oysters, etc.], and so on) that can reduce or entirely avoid the above-mentioned problems of infection, escape, contamination, etc. A system in which the average number of months in the sea is reduced and where one has full control of all logistics to and from the fish farms will be the key to a sustainable growth in the aquaculture industry.
The loss/waste situation for all fish stocked in fish farms according to the prior art is:
6.1% mortality due to poor smolt quality.
6.0% mortality due to the conditions at the locality.
3.8% mortality due to contracted disease.
Preventative solutions are robust smolt, good localities, measures for preventing infection and gentle handling.
The future for the Norwegian and international fish breeding industry faces major challenges, and the present invention could thus open up possibilities that could develop/lead the industry in a sustainable and environmentally friendly direction.